Effect of Impurities on the Anomalous Transport Properties of NbSe3

Abstract

Studies on the effect of charged (Ti) and uncharaged (Ta) impurities on the non-Ohmic behavior of and microwave absorption in Nb${\mathrm{Se}}_3$ show that (1) the characteristic field $E_0$ increases as $c^2$ ($c=\mathrm{Ta}\mathrm{concentration}$), in agreement with a recent calculation by Lee and Rice; (2) the microwave absorption is suppressed by impurities; and (3) charged impurities are strikingly more effective in supressing the anomalous properties. These conclusions provide very strong evidence for Fröhlich sliding-mode conductivity in the nominally pure compound.